If you can't update by going back to stock and use the update device in settings -> about, then you can download it and use Odin to flash. I will wait for a rooted ICS themed version from one of the talented devs

XDA Developers was founded by developers, for developers. It is now a valuable resource for people who want to make the most of their mobile devices, from customizing the look and feel to adding new functionality.Are you a developer?